Abstract
The potential of a thermal neutron imaging system based on a composite neutron convertor foil combined with a low-pressure, multistep avalanche chamber is demonstrated. Neutron-induced charged particles from a primary convertor element induce multiple low-energy electrons escaping from a second thin film of high electron-emissive material. We investigated the performance of detectors with Gd- and Li-based primary convertors coated with CsI as a secondary electron emitter. It is shown, that the detector can be operated with high stability at a sufficiently high gain to detect all escaping particles. A localisation resolution of 0.4 mm (fwhm) was obtained. With Li-based convertors a very low γ-ray sensitivity was established. The good imaging performance, free of parallax errors in divergent neutron beams, fast time resolution, low occupation time and high count rate capability, make this instrument an excellent tool for time-resolved neutron scattering experiments and for neutron radiography and tomography.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
